Erythema multiforme

Abstract

Erythema multiforme (EM) is an acute, self-limited cutaneous or mucocutaneous disorder, characterized by the development of symmetrically distributed, fixed, red lesions. Some lesions evolve concentric zones of color to form “targets,” the hallmark of EM. The spectrum of disease known as erythema multiforme includes the more common and familiar form, designated EM minor (von Hebra), and a more serious mucocutaneous process, designated EM major (Stevens-Johnson syndrome). Both forms of EM may follow a number of precipitating factors, primarily infections or drugs. EM minor most frequently follows an infection with herpes simplex virus (HSV), and in those cases, the disease often recurs with subsequent HSV infection. Recently, the presence of HSV specific antigens and nucleic acids were demonstrated within the epidermis of cutaneous lesions of recurrent EM minor. These findings, together with results of immunopathology studies, support the concept that EM lesions may result from an immune-mediated response to HSV present in the skin at those sites. In EM major, drug exposure is more frequently the precipitating factor. There is evidence to suggest that in those cases, a toxic mechanism directed at the skin may be important. Recent studies carefully detailing the usual clinical course and histologic features of EM, together with investigative studies examining potential pathomechanisms, have begun to yield a clearer picture of this disease process such that a more rational approach to therapy is now possible.